Joint for tubular concrete members and the like



'July 26, 1932. N. c. JOHNSON 1,869,105

JOINT FOR TUBULAR CONCRETE MEMBERS AND THE LIKE Origin l Filed June 30,1928 WWW Patented July 26, 1932 UNITED STATES NATHAN C. JOHNSON, OFENGLEWOOD, NEW JERSEY JOINT FOR TUBULAR CONCRETE MEMBER-S AND THE LIKEApplication filed .Tune 30, 1928, Serial This invention relates to animproved joint construction for tubular members of concrete or the like,such as concrete piping, and to methods of forming such oints. V

The objects of this invention include the provision of eflicient,durable and relatively inexpensive joining means and methods of theclass above indicated.

Further and more specific objects, features and advantages will clearlyappear from the detailed description given below, taken in connectionwith the accompanying drawings which form a part of this specificationand illustrate by way of example certain embodiments of the invention.

The invention consists in the novel features and arrangements embodiedby way of example in the constructions herein described as illustratingpreferred forms of the invention, together with such novel methods asare also hereinafter described.

In the drawing Fig. 1 is a View partly in section and partly broken awayof the cooperating joining portions of concrete pipmg prepared accordingto one phase of my invention;

Fig. 2 illustrates the manner of cementing together the parts shown inFig. 1; and

Figs. 3 and 4 are views similar to Fig. 1, but showing alternativeembodiments of my invention.

In Fig. 1 male and female joining portions of concrete piping areindicated at 10 and 11. Except for the joining portions hereinafterdescribed, this piping may be constructed substantially according towell known methods. That is, the same may be molded of concrete or othersuitable cementitious material and if desired, suitable reinforcingmeans as at 12 may be incorporated; The exterior surface 13 at the endof the portion 10 and also the interior surface 14: at the end of thepor tion 11 may be treated during or soon after the molding process in amanner such as to expose to a considerable degree the coarser aggregateparticles of the concrete or other mixture. Certain methods for thustreating these surfaces are fully described in my Pat ents, No.1,687,321, entitled Method of and composition for treating concrete,issued 110,289,438. Renewed April 11, 1932.

July 26, 1927, and Nb. 1,668,723, entitled Process of and means forcementitious molding, issued May 8, 1928. According to such processesthe concrete surface is treated with a suitable medication to delay orprevent the setting of the cement at the surface layers so that afterthe main body of the concrete is hardened, such surface layers of cementmay be brushed or washed away, leaving the stone or other aggregrateparticles exposed to the 30 desired degree. In the drawings Figs. 1 and2 indicate the manner in which the coarser aggregate particles may bemade to prominently protrude from-these surfaces. 7

The portions 10 and 11 may be telescoped in the usual manner asindicated in Fig. 2 and the intervening space between the areas 13 andll may be filled with a suitable cement, which upon hardening, serves tointerlock the aggregate particles projecting m from the surfaces of thetwo members. The multitude of irregular shaped protruding aggregateparticles thus not only provide desirable bonding areas coperating withthe cement 15, but also provide a large number .75 of members equivalentto clinching means, securing the two sections of pipe againstlongitudinal separation. Thus, an interlocking joint is provided withoutnecessarily resorting to the expedient of extending the reinto forcingmeans into the joint. Hence if minor cracks or fissures should appear atthe joint, for example, as a result of displacements of the pipe as timegoes on, there will be no re inforcing means to become exposed and corroded at the joint. Furthermore, the body of sealing cement 15, beingannular in form and interlocked as above described, cannot possiblyunder proper conditions, work loose from the joint either as a whole orin part. 9% The joints between the sections of pipe may accordingly bemade with substantially the same'or a greater degree of permanency andstrength, as the other portions of the pipe.

If clean, relatively sharp aggregate stone 9. is used at the surfaces 13and 14, a true and water-tight union between the two surfaces may beformed when mortar of the proper grade is poured in In the embodiment ofthe invention illustrated in Fig. 8, the inside surface 16 and theoutside surface 17 at the ends of the female and male portions 18 and 19respectively may be made with a series of shallow grooves as at 20, soas to interlock with the sealing cement. The grooves 20 in theparticular form shown may be made by lining the concrete molds withannular pieces of expanded metal either treated or untreated with setdelaying medication, such as disclosed in the above mentioned patents.As the piping is removed from the molds, the expanded metal may also beremoved, leaving a pattern of grooves in the concrete surfacecorresponding to the pattern of the expanded metal. The grooves may bemade with a somewhat larger cross-sectional area if the expanded metalis medicated with the set delaying material and also the use of suchmaterial facilitates ready removal of the expanded metal without dangerof cracking the peripheral edges at'the ends of the pipe. To give theoutermost peripheral edges greater strength, the grooves may be thereomitted as indicated at 21 and 22.

According to the embodiment of the invention shown in Fig. 4, female andmale pipe'portions 23 and 2 are formed with 00- operating. areas 25 and26 respectively formedin a manner similar to the above describedmembers, but using a relatively wide mesh burlap or inexpensive cloth inlieu of the use of expanded metal. That is, the burlap or clothpreferably after treatment with medicated material, such as disclosed inmy above mentioned patents, is applied to the surfaces of the molds soas to provide a pre determined grooved pattern as shown in the drawings.After the molds have-been removed, the burlap or cloth may be readilystripped off, especially if it has been medicated. Then to join the pipesections, the areas 25 and 26 may be broughtinto engagement and sealedtogether with cement, which will interlock with the grooves and form apermanent tight oint.

While the invention has been described in detail with respect toparticular preferred examples thereof which give satisfactory results,it will be understood by those skilled in the art after understandingthe invention, that various changes and modifications may be madewithout departing from the spirit and scope of the invention and it isintended therefore in the appended claim to cover all such changes andmodifications.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

The method of sealing telescoped tubular members, which comprises,molding concrete tubular members, treating the surfaces to be sealedwith a set delaying agent, removing the resulting unset cement of theconcrete when the members are set, and sealing and interlocking saidsurfaces by introducing cement between the same.

In testimony whereof I have signed my name to this specification.

NATHAN C. JOHNSON.

